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using System.Collections.Generic;

namespace GitSharp.Core.Transport
{
    public static class RefFilterContants
    {
        /// <summary>
        /// The default filter, allows all refs to be shown.
        /// </summary>
        public static RefFilter DEFAULT = new DefaultRefFilter();

        private class DefaultRefFilter : RefFilter
        {
            public IDictionary<string, Ref> filter(IDictionary<string, Ref> refs)
            {
                return refs;
            }
        }
    }

    /// <summary>
    /// Filters the list of refs that are advertised to the client.
    /// <para/>
    /// The filter is called by {@link ReceivePack} and {@link UploadPack} to ensure
    /// that the refs are filtered before they are advertised to the client.
    /// <para/>
    /// This can be used by applications to control visibility of certain refs based
    /// on a custom set of rules.
    /// </summary>
    public interface RefFilter
    {
        /// <summary>
        /// Filters a {@code Map} of refs before it is advertised to the client.
        /// </summary>
        /// <param name="refs">the refs which this method need to consider.</param>
        /// <returns>the filtered map of refs.</returns>
        IDictionary<string, Ref> filter(IDictionary<string, Ref> refs);
    }
}